The traditional sling seat found in the foldable wheelchair suffers from numerous drawbacks. When a person sits in a wheelchair with a sling shaped seat, an unfavorable relationship between the hip and spine develops. The pelvis shifts into a posterior pelvic tilt which results in discomfort, lower back pressure and a strong tendency to slide forward.
There has been considerable evolution from the early sling support straps developed for use in wheelchair seating. Development recently has taken place in which contoured seat and back surfaces, designed to relieve pressure spots, have been provided to ensure a comfortable environment for the patient's well-being and productivity. These seating systems are sometimes detachable from the wheelchair base, while others simply sit on top of the slings.
Present wheelchair seating systems sometimes use rigid frames which do not allow for changing the position of the user, e.g. changing the angle of and between the seat and back positions. Some wheelchair seating arrangements have allowed for variation in the angle of tilt, but use complicated and expensive parts, adapted to fit a conventional wheelchair base.
Further, conventional cushions for seat and back portions of wheelchair support systems, even those filled with gel, air or foam, do not take into account the individual size and shape distinctions between the musculature and skeletal variations found from individual to individual patient.
Variation in tilt angle of the seat and the back of a wheelchair support system is important. Changing the tilt angle provides a redistribution of the weight and a reduction of pressure related problems such as pressure sores and the like.
Harness systems are desirable to prevent patient slumping and the musculature and skeletal related problems caused by slumping. For example, patients can sometimes slump side to side, slump forward, or slide posteriorly forward in the chair if they are not safely harnessed in. Such harnesses, however, should provide for quick and easy release by the patient in case of emergency.
A wheelchair support system should have all the advantages herein described, as well as the ability to be quickly and toolessly removed without altering the adjustments previously made to the wheelchair system to fit individual patients. That is, when the physical therapist first fits the system to the patient adjustments are made for fitting the individual patient's body frame with respect to the needed floor length, seating depth and femur length, as well as tilt requirements before appropriate pressure relief on the spine and buttocks. When the system is quick released from the wheelchair frame for transportation, it does not interfere with a change to these adjustments.
Molded bases, combined with moldable foam cushions allow the seat and back to conform to the individual anatomy of the patient, providing continuous custom fit, even as the patient shifts about in the chair. The molded foam, when combined with the molded ABS base seat and back, must be correctly positioned to avoid pressure in the coccyx, sacral or spinal area. That is, the seat and back of the wheelchair support system must distribute and download pressure from bony protuberances to reduce the risk of pressure sores.
It is further desirable to provide a seating system that will decrease the inter-discal pressure in the lumbar portion of the spine, thereby creating proper lordotical curvature.
In short, the desirable seat, cushion, adjustment and harness features described above are highly desirable and do not heretofore appear in a single seating system. Moreover, to provide the advantages set forth above in a system which is quickly, easily and toolessly removable from the frame of a wheelchair without changing the adjustment settings, without interfering with adjustments in tilt and adjustments to accommodate patient's individual body frame and measurements which provides additional advantages. The features described above will assist in skeletal alignment, enhance comfort and decrease fatigue, while increasing the ability of a patient to sit in a chair for long periods.
Last, further advantages are provided for in a system with all the features set forth above which is easily fitable to a standard, conventional wheelchair frame with only the use of simple hand tools and which further provides easy removal of the wheelchair support system for transfer of the system from one wheelchair frame to another.
The advantages set forth above and other objects are provided for in the present invention which provides a seating system that replaces the slings and is easily attached to and removed from the frame of a conventional wheelchair.
It is another object of the present invention to provide for a wheelchair support system attachable to the frame of a wheelchair and having a rectangular seat and back which include contour molded bases.
It is another object of the present invention to provide for a wheelchair support system which has a generally rectangular base and back and additionally provides a harness for securing the patient to the seat and back, the harness having lap belt and shoulder straps secured to the frame of the wheelchair.
It is an additional object of the present invention to provide for a wheelchair support system having a rectangular seat and base, for attachment to the frame of a wheelchair where the attachment provides easy release from the frame and further provides for adjustment of the seat and back with respect to the frame of the wheelchair.
It is further object of the present invention to provide for a wheelchair support system capable of being attached and removed from the wheelchair frame without drilling, welding, cutting, or otherwise defacing or altering the wheelchair frame, and without altering the adjustment settings.
It is yet another object of the present invention to provide for an adjustable, removable wheelchair support system for attachment to the frame of a wheelchair, the wheelchair support system comprising of a seat and a back which are adjustable up and down, for and aft and in angular relationship between the seat and back.
It is still another object of the present invention to provide for an adjustable, removable wheelchair support system with a seat comprised of foam, selected by patient weight, which softens and deforms on contact with a warm, dermal surface of the patient to provide for an even distribution of the weight of the patient upon the seat.
It is yet another object of the present invention to provide for an adjustable, removable wheelchair support system having a seat and a back made of molded ABS, the seat having a depression positioned beneath the coccyx of the patient and the back having a channel rearward of the spinal column of the patient to prevent pressure buildup in the skin and tissue area adjacent bony protuberances.